• Journal of Life Science
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• v.31 no.4
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• pp.400-409
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• 2021

Sanguinarine, a natural benzophenanthridine alkaloid, has been considered a potential therapeutic target for the treatment of cancer because it can induce apoptosis in human cancer cells; however, the underlying mechanisms of action still remain unclear. Tumor suppressor p53 deletion or mutation is an important reason for the resistance of colorectal cancer cells to anticancer agents. Therefore, in the present study, the role of p53 during apoptosis induced by sanguinarine was investigated in p53wild type (WT, p53+/+) and p53null (p53+/+) HCT116 colon carcinoma cells. Sanguinarine significantly caused greater reductions in cell viability in HCT116 (p53+/+) cells than in HCT116 (p53-/-) cells. Consistently, sanguinarine promoted more DNA damage and apoptosis in HCT116 (p53+/+) cells than in HCT116 (p53-/-) cells while increasing the expression of p53 and cyclin-dependent kinase inhibitor p21^WAF1/CIP1. Sanguinarine increased the activity of caspase-8 and caspase-9, which are involved in the initiation of extrinsic and intrinsic apoptosis pathways, respectively, and it activated caspase-3, a typical effect caspase, in HCT116 (p53+/+) cells. Sanguinarine also increased the generation of reactive oxygen species (ROS), and the Bax/Bcl-2 ratio, while destroying the integrity of mitochondria in HCT116 (p53+/+) cells, but not in HCT116 (p53-/-) cells. Overall, the results indicate that sanguinarine induced p53-dependent apoptosis through ROS-mediated activation of extrinsic and intrinsic apoptotic pathways in HCT116 colorectal cancer cells.

• Korean Journal of Breeding Science
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• v.43 no.3
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• pp.214-217
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• 2011

A light pink double freesia (Freesia hybrida Hort.) 'Pink Ribbon' was developed from a cross of breeding a line, 'Pink Jewel' derived 'Michelle' and 'Rossini' and 'Purple Rain' followed by seedling and line selections at the National Institute of Horticultural and Herbal Science (NIHHS), Rural Development Administration (RDA) in 2008. Growth and flowering characteristic tests were conducted from 2004 to 2007. 'Pink Ribbon' has double type flower with light pink color (RHS, RP66C). It has simultaneous flowering of many florets, good flower shape, upright leaves and stalks. The average cut flower yield of 'Purple Rain' observed in the greenhouse from 2005 to 2007 was 7.7 cuttings per plant. It has good production of cormlets, vigorous growth, too. 'Purple Rain' could be cultured under greenhouse conditions in Korea.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.196-200
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• 2008

A new spary chrysanthemum (Dendranthema grandiflorum) cultivar 'Pinky' was bred from a cross between 'Rima' and 'Yen'. Progenies were investigated from 2004 to 2006 under shading culture in spring and retarding culture in autumn and the promising line was selected based on the performance of year-round production, white rust resistance and vase life. Pinky flowered around 20 October, and year-round production was possible by shading and lighting. Its flower was 3.1 cm in diameter, and had 38.4 petals and 26.8 flowers per stem in autumn. Its petal was narrow (0.4 cm) and pink with green in color at the flower center. Days to flower from short-day start for 'Pinky' was about 47 in spring. 'Pinky' showed a vase life of 20.9 days in autumn. This cultivar was commercially registered in 2007. 'Pinky' would be suitable for culture under the greenhouse and rain shelter condition in Korea.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.248-251
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• 2010

A lemon double freesia (Freesia hybrida Hort.), 'Shiny Lemon' was developed from a cross between the domestic breeding lines ('Golden Crown' and 'White Wings') and 'Yvonne' followed by seedling and line selections at the National Institute of Horticultural and Herbal Science, Rural Development Administration (RDA) in 2007. Growth and flowering characteristic tests were conducted from 2003 to 2006. 'Shiny Lemon' has large double type flower with lemon color (RHS Y13D). It has multiple florets, good flower shape, and upright leaves and stalks. The average cut flower yield of 'Shiny Lemon' was 7.1 cuttings per plant in the greenhouse from 2005 to 2007. Additionally, it has good production of cormlets and vigorous growth. 'Shiny Lemon' could be cultured under greenhouse conditions in Korea.

• Korean Journal of Breeding Science
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• v.43 no.3
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• pp.210-213
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• 2011

A dark pink semi-double freesia (Freesia hybrida Hort.) 'Happy Birthday' was bred from a cross between 'Pink Jewel', F1 progeny of 'Michelle' and 'Rossini' as a female and 'White Lace' as a male parent. Test for the growth vigor and flowering characteristic were conducted from 2002 to 2007. A new variety 'Happy Birthday' has semi-double flower type with dark pink color (RHS color chart #RP66C). It has multiple flowers, distinctive flower shape, upright leaves and also stalks. The average yield of this variety 'Happy Birthday' counted over 6.7 stems per plant per season in the standard greenhouse cultivation method. It has also good production of cormlets, vigorous growth. A new variety 'Happy Birthday' is suitable for the greenhouse conditions during winter season in Korea.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.451-455
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• 2009

Lilium lancifolium, which is one of the Korean native lilies, possesses several useful genetic characteristics such as growth vigor, bulbil formation and resistance to Fusarium. Hybridization was performed to insert useful traits of Asiatic hybrid "Dreamland" as the male parent with upward direction and dark brown spotless on the petal into L. lancifolium as the female parent. The rate of pollen germination of L. lancifolium and "Dreamland" were 30% and 60%, respectively. The pollen germination ratio of $F_1$ progenies at flowering date was 25-57%, which is between the parents'pollen germination ratio. The individual flowering time was between 113 days and 131 days after planting. Of 99% of all plants, the leaf shape index was more than five, which means that the leaf shape of $F_1$ plants is more influenced by female than male parent. The flower color was separated into four types. 51.5% of the progenies showed orange and 44.2% showed light orange, respectively. The colors seemed to be highly influenced by female parents. Mixed colors of parents, orange yellow and light yellow orange, were 3.1%, 1.2%, respectively. Flowering directions were segregated by three different ways, upside, side, and downside. Side direction, which is medium type between female and male parent, was 73%. All progenies showed lots of spot on petals except one offspring. The percentage of bulbil formation on leaf axil was 49.4%. Among those, the maximum number of bulbil formation was 25. The mean number of bulbil formation per plant was five.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.3
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• pp.201-206
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• 2019

This report constitutes the first demonstration in Korea of single-crystal lateral gallium oxide ($Ga_2O_3$) as a metal-oxide-semiconductor field-effect-transistor (MOSFET), with a breakdown voltage in excess of 480 V. A Si-doped channel layer was grown on a Fe-doped semi-insulating ${\beta}-Ga_2O_3$ (010) substrate by molecular beam epitaxy. The single-crystal substrate was grown by the edge-defined film-fed growth method and wafered to a size of $10{\times}15mm^2$. Although we fabricated several types of power devices using the same process, we only report the characterization of a finger-type MOSFET with a gate length ($L_g$) of $2{\mu}m$ and a gate-drain spacing ($L_{gd}$) of $5{\mu}m$. The MOSFET showed a favorable drain current modulation according to the gate voltage swing. A complete drain current pinch-off feature was also obtained for $V_{gs}<-6V$, and the three-terminal off-state breakdown voltage was over 482 V in a $L_{gd}=5{\mu}m$ device measured in Fluorinert ambient at $V_{gs}=-10V$. A low drain leakage current of 4.7 nA at the off-state led to a high on/off drain current ratio of approximately $5.3{\times}10^5$. These device characteristics indicate the promising potential of $Ga_2O_3$-based electrical devices for next-generation high-power device applications, such as electrical autonomous vehicles, railroads, photovoltaics, renewable energy, and industry.

• Journal of the Korean Geotechnical Society
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• v.34 no.12
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• pp.29-42
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• 2018

Shale and mudstone in Daegu-Gyungbuk area have low strength and resistance to weathering compared to other rocks. Therefore, it is necessary to evaluate their strength depending on the degree of saturation and crack development. In this study, shales and mudstones were collected from several construction sites in Daegu-Gyungbuk area. Their basic material properties such as porosity, SEM, chemical component, and durability were tested. A porosity (absorptivity) of mudstone was 31% (25%), which was 6 (8) times higher than that of shale. Some mudstone was easily disintegrated with water and it consisted of highly-active clay mineral such as smectite type. These rocks were prepared by small cube specimens for unconfined compression test. An unconfined compressive strength of dry rock was compared with saturated one. Microwave oven was operated step by step to stimulate void water within a saturated rock, which resulted into high temperature and micro crack initiation within rocks. A strength of microwaved rocks was compared with operation time and crack initiation. As a result, the average unconfined compressive strength of dry and saturated shale was 62 and 33 MPa, respectively. The strength of mudstone for each condition was 11 and 4 MPa. When a rock became saturated, its strength decreased by 47% and 64% for shale and mudstone at average. In addition to saturation, a rock was in the microwave for 15 secs, its strength decreased into 49% for shale and 52% for mudstone. When a microwave oven operated up to 20 sec, a rock was crushed into several pieces and its temperature was approximately 200 degrees.

• Journal of Platform Technology
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• v.6 no.4
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• pp.59-68
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• 2018

The objective of this study is to develop an embedded antenna structure with NFC and WPC composite functions. By selecting stable materials, the optimal component ratio of the polymer sheet was determined. The low cost embedded winding method compared to the existing FPCB was devised. During the winding process, characterization and process technology were developed. We also fabricated a ferrite mold to process the WPC grooves and developed the process technology for optimizing the WPC antenna. The following conclusions were obtained. (1) Optimum composition ratio was derived as Fe 87.5%, Si 7%, Al 5.5% and selected as the final material. (2) Optimal sheet conditions were derived from the experimental evaluation method and the experimental design method through the combination test of the optimized sheet and the conventional mass production FPCB. (3) According to coil diameter and inner diameter, Q value fluctuation, resistance value and efficiency fluctuation are obtained. Therefore, the most suitable coil condition is selected and Rx matching is performed. (4) The EMV load modulation test and the cognitive distance test of the polymer sheet and the ferrite sheet showed that the recognition distance of the polymer sheet at 1k and 4K was 32-33 mm and the recognition distance of the ferrite sheet at the same condition was 30-31 mm.

• Journal of Pharmacopuncture
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• v.22 no.1
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• pp.28-34
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• 2019

Background: Breast cancer is a complex, heterogeneous disease and one of the most common malignancies in women worldwide. The efficacy of chemotherapy as an important breast cancer treatment option has been severely limited because of the inherent or acquired resistance of cancer cells. The molecular chaperone heat shock protein 90 (HSP90) upregulated in response to cellular stress is required for functions such as conformational maturation, activation and stability in more than 200 client proteins, mostly of the signaling type. In this study, the expression of HSP90 isoforms including $HSP90{\alpha}$ and $HSP90{\beta}$ in breast cancer cell lines before and after treatment with doxorubicin (DOX) was assessed. Material and Methods: The cell cytotoxicity of DOX in MDA-MB-231 and MCF-7 cell lines was determined using the MTT assay. immunofluorescence and western blotting techniques were used to determine the expression of $HSP90{\beta}$ in the cell lines before and after DOX treatment. Immunofluorescence was also conducted to ascertain the expression of $HSP90{\alpha}$. Results: The MTT assay results showed that the MDA-MB-231 cells ($IC_{50}=14.521{\mu}M$) were more sensitive than the MCF-7 cells ($IC_{50}=16.3315{\mu}M$) to DOX. The immunofluorescence results indicated that the expression of $HSP90{\alpha}$ in both cell lines decreased after exposure to DOX. The western blot and immunofluorescence analyses showed that $HSP90{\beta}$ expression decreased in the MCF-7 cells but increased in the MDA-MB-231 cells after DOX treatment. Conclusion: The obtained results suggested that $HSP90{\alpha}$ and $HSP90{\beta}$ expression levels were reduced in the MCF-7 cells after exposure to DOX. In the MDA-MB-231 cells, $HSP90{\alpha}$ expression was reduced while $HSP90{\beta}$ was found to be overexpressed following DOX treatment.